Spherical bearing construction

ABSTRACT

Spherical bearings are provided which include a socket incorporating a spherical race and spherical bearing member which is fabricated from a continuous helix threadably inserted into the spherical race of the socket. The ball and socket construction can be incorporated in such structures as rod end bearings or in any applications where movement of the ball with respect to the socket is indicated. The method of fabricating the spherical bearing member includes the steps of forming a helix, compressing the coils of the helix into engagement with one another and generating a spherical surface on the exterior surface of the helix to provide the spherical bearing member. The helix may be fabricated from an appropriate size of strip stock or, may be alternatively fabricated by the generation of the helix on a cylindrical body from which it is subsequently stripped. The latter method of fabricating the helix is particularly suitable where materials in strip form for forming the helix are not sufficiently ductile.

United States Patent Campbell 1 Aug. 1,1972

[54] SPHERICAL BEARING CONSTRUCTION [72] Inventor: James R. Campbell,South Laguna,

' Calif.

[73] .Assignee: Armco Steel Corporation,

Middletown, Ohio a part interest [22] Filed: May 22, 1970 [21] Appl.No.: 39,579

[52] US. Cl ..308/72 [51] Int. Cl. ..Fl6c 13/04 [58] Field of Search..308/72 [56] References Cited UNITED STATES PATENTS 2,753,225 7/1956Gilmer ..308/72 3,240,502 3/1966 Snyder ..308/72 3,482,890 12/1969Burrell ..308/72 Primary Examiner-Martin P. Schwadron AssistantExaminer-Frank Susko Att0rney-Fulwider, Patton, Rieber, Lee & Utecht[57] ABSTRACT Spherical bearings are provided which include a socketincorporating a spherical race and spherical bearing member which isfabricated from a continuous helix threadably inserted into thespherical race of thesocket. The ball and socket construction. can beincorporated in such structures as rod end bearings or in anyapplications where movement of the ball with respect to the socket isindicated.

The method of fabricating the spherical bearing member includes thesteps of forming a helix, compressing the coils of the helix intoengagement with one another and generating a spherical surface on theexterior surface of thehelix to provide the spherical bearing member.The helix may be fabricated from an appropriate size of strip stock or,may be alternatively fabricated by the generation of the helix on acylindrical body from which it is subsequently stripped. The lattermethod of fabricating the helix is particularly suitable where materialsin strip form for forming the helix are not sufficiently ductile.

17 Claims, 17 Drawing Figures PATENTEDAUG 1 I972 3.680.930

sum 1 or 3 FIG. 2. FIG, 3.

W J PW 22 ill-Id M B 20 I4 24/ 24 g 16 22 H FIG. 4. ,1 m L H PM ml Mill20 FIG. 6. FIG. Z I -z 42 r I I4 54 56 i? 52 Z I F=\44 M FIG. 8. 7 I 62S g 1 k 64 1 T 1 WW 7 Hll||ll+\ [///Z\\/ 1 6 INVENTOR Z" E 'EII E 5JAMES R. CAMPBELL {Q $5!" BYMAHONEY, HORNBAKER 38 dig QQQ AND SCH/CKATTORNEYS PATENTEDAus 1 I972 3.680.930

. INVENTOR.

JAMES R. CAMPBELL BYMAHO Y, HORNBAKER I A .SCHICK ATTORNEYS PATENTEDMJB11912 I 3.680.930

SM! 3 OF 3 FIG. [3.

, -IO6 loz JAMES R. CAMPBELL BYMAHONEY, HORNBAKER AND SCH/CK A T TORNEYSSPHERICAL BEARING coNs'rRUc'rroN BACKGROUND OF THE INVENTION Thisinvention relates to a spherical bearing construction and to methods offabricating the same and is directed particularly to bearings of theball and socket type wherein the socket incorporates asphericallygenerated race and wherein the spherically-generated race isadapted to receive a correspondingly generated spherical bearing member.

Devices of this type are frequently incorporated in structures known asrod end bearings wherein the ball and socket are connected to theextremity of a rod or linkage to provide a universal connection withanother object. They are used extensively in controlled linkage systemsand other mechanisms to provide articulated joints between the links,levers and the like with which they are associated. The spherical balland socket construction has the advantage of providing, withinpredetermined limits, universal angulation or swivelling of the linkagemembers to accomplish self-alignment of the associated moving parts.

Spherical bearings of the type under consideration are applied inlinkage systems because they eliminate looseness and slop by virtue oftheir relatively large ball and socket bearing surfaces and theirrelatively precise fit. In addition, the limited angulation or swivelaction provided by such bearings eliminates binding and undesirableloads from linkage systems in which'they are incorporated.

In order to illustrate the construction and mode of operation of thespherical bearing of the invention, it will be described as incorporatedin a rod end bearing construction but it will be obvious to thoseskilled in the art that the teachings of the invention may be appliedwith equal cogency to other bearing applications and it is not intendedto limit the bearing construction of the invention or the method thereofto the specific embodiment disclosed and described herein.

There are numerous rod end bearing on the market at the present time,but all of them appear to be subject to certain deficiencies whichdetract seriously from their continued efficient performance. Most rodend bearings are assembled by press fitting or swaging operations underheavy pressure.

Generally speaking, the spherical bearing member is fabricatedseparately from the spherical socket intended to receive it and issubsequently inserted in the spherical socket which may be provided withone flanged side and one open side. The open side is subsequently swagedinto overlying relationship with the contiguous end of the sphericalbearing member to formed. Similarly, if the spherical bearing member istoo loosely secured in the corresponding spherical socket, undesirablelooseness in the linkage will occur accompanied by excessive play of thespherical bearing member in the socket and consequent fretting whichultimately results in premature failure of the bearing.

OBJECTS AND SUMMARY OF THE INVENTION It is, therefore, an object of theinvention to provide a ball and socket bearing in which the sphericalball member is inserted into the spherical socket member without theutilization of a swaging process or any similar process which willentail resulting uncertainty as to the tolerance to be maintainedbetween the periphery of the spherical ball member and the correspondingspherical race in the socket member.

Another disadvantage of conventional rod end bearing constructions isthe fact that once the spherical bearing member becomes worn, it isimpossible to remove and replace the worn spherical bearing member witha new spherical bearing member. 7

Another problem encountered with conventional ball and socket rod endbearing constructions which are fabricated by swaging the sphericalbearing member in the spherical socket is the problem of utilizingmaterials which are specifically suited for the applications in whichthe rod end bearing is to be utilized. For instance, in the swagedconstructions, it is necessary to utilize metals in the spherical socketmember which can be readily swaged into overlying relationship with thejuxtaposed side or extremity of the spherical bearing member. Suchmetals susceptible to swaging are not necessarily those most suitablefor particular applications where anti-galling characteristics, elevatedtemperatures or other ambient phenomena of an extreme nature may beencountered. In addition, it is quite common to fabricate, for reasonsof economy, the spherical ball members or the race from sintered metalor the like.

Such sintered spherical bearing members are susceptible to excessivewear and to relatively premature deterioration which results in thenecessity for discarding the entire assemblage. In addition, it isalmost impossible to fabricate the external sphericity of the ballmember into precise correspondence with the sphericity of the race ofthe socket member.

As an alternative to swaging the spherical socket in operativerelationship with the spherical bearing member, certain ball and socketbearings are fabricated by providing a slot in a side wall of thespherical socket and inserting a suitably formed spherical bearingmember thorugh the orifice. Subsequently, the spherical bearing memberis adjusted in the socket to prevent it from being released therefromwithout the deliberate intent of a person disassembling the sphericalbearing member from the spherical socket.

Unfortunately, the utilization of this type of construction producesstress concentrations in the spherical socket since a significant notcheffect is created by the insertion orifice or slot in the sphericalsocket.

Consequently, conventional ball and socket bearings are characterized bythe fact that the types of metals which can be utilized in the ball andsocket are limited by the necessity for swaging the socket in operativerelationship with the ball or by the necessity for providing a loose fitbetween the ball and socket attributable to the insertion of the ball toaccess openings in the side of the socket or to grooves in ball surfaceto provide admittance into the race. In addition, where the ball isswaged in operative relationship with the socket, close tolerancescannot be achieved because of the unpredictability of the swagingoperation. Moreover, the ball or socket cannot be removed from operativerelationship with each other if they have been swaged together and theentire assemblage must be discarded.

It is, therefore, a further object of the invention to provide a balland socket bearing wherein the spherical bearing member is fabricatedfrom a continuous helix having a spherical surface generated on theexternal surface thereof and wherein the spherical socket member isadapted to have the helical spherical bearing member threaded intooperative engagement with it thus eliminating the swaging operation orthe insertion openings incorporated in prior art constructions.

A further object of the invention is that a spherical bearing can beproduced which is, due to the lack of residual stresses caused inmanufacture and the absence of stress risers due to notches,structurally more efiicient and thus smaller and lighter thanconventional spherical bearings.

A natural concomitant of the above described ball and socket bearingconstruction is that the spherical socket and spherical bearing membercan be fabricated from any desired material so long as the sphericalsocket can be forged or otherwise shaped from the desired material andso long as the material of the spherical ball member is susceptible offormation in a helical configuration.

Another object of the invention is the provision of a ball and socketbearing construction wherein the external sphericity of the sphericalbearing member can conform precisely to the internal sphericity of thesocket member due to the fact that the corresponding sphericities can bedetermined prior to the threadable insertion of the spherical bearingmember into operative relationship with the corresponding sphericalbearing surface of the socket member.

Consequently, the lack of precision and the sloppiness characteristic ofprior devices are eliminated and the consequent excessive and prematurewear of the ball and socket bearing construction is obviated.

An additional advantage of the construction of the invention lies in thefact that the helically configured spherical ball member can be asreadily removed from the socket member as it is inserted therein bysimply threading outwardly from the socket member. Therefore, if, forany reason, the necessity for replacing either. ball or socket memberoccurs, it can be readily accomplished without the necessity fordiscarding the entire assembly.

Another object of the invention is the provision of a helicallyconfigured spherical ball member for use in conjunction with acorrespondingly configured socket member which is fabricated from acomposite material, that is, wherein the helix is coated with a suitablecoating, such as trifluroethylene sold under the trademark Teflon orwherein the material'utilized is constituted by a laminate of dissimilaror corresponding metals.

In addition, the corresponding and adjacent coils of the helix areparticularly adapted for reception of various types of lubricants whichmaterially enhances the viable life of the ball and socket assemblage inwhich:

the helical ball member is inserted.

An additional object of the invention is a method of fabricating a balland socket bearing construction wherein a helix iscreated from a desiredmetal or other material and wherein the adjacent coils or turns of thehelix are compressed into contact with one another to permit a sphericalsurface to be generated on the compressed helix. The helical ball memberis then threaded into a correspondingly spherical socket and is retainedin operative relationship with said socket until the deliberate removalof the ball member from operative relationship with the socket member.

An additional object of the invention is the provision of a ball andsocket member of the preceding character wherein the sphericallygenerated helical ball incorporates a bore and a bushing is inserted insaid bore adapted to maintain a shaft, bolt, or other member inoperative relationship with the ball member. In order to preventrelative rotation between the bushing and the bore of the helicallygenerated ball member, the bore of the helix and the periphery of thebushing may be correspondingly splined or otherwise joined in operativenon-rotatable relationship.

Another object of the invention is that various hard surfaces, incapableof being deformed without cracking or chipping or flaking, may bereadily applied to either or both the race surface or the ball surface,precisely finished to contour and subsequently assembled into a finishedarticle without damage to the hard surface.

An additional object of the invention is the provision of a sphericalbearing with a predetermined amount of preload between ball and racewhich can be produced for applications requiring zero play or zeromushing of a plastic interface.

Other objects and advantages of the invention will be apparent from thefollowing specification and the accompanying drawings which are for thepurpose of illustration only.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of arod end bearing incorporating the teachings of the invention;

FIG. 2 is a vertical sectional view taken on the broken line 2-2 of theFIG. 1;

FIG. 3 is a vertical, partly sectional view of the ball member of therod end bearing;

FIG. 4 is a vertical, partly sectional view of a compressed helicalmember prior to the generation of the spherical surfaces thereupon toprovide the ball member of FIG. 3;

FIG. 5 is a developmental view showing the typical reduction in theradial width of the strip incorporated in the helix resulting from thegeneration of the spherical external surface thereupon;

FIG. 6 is an enlarged, partly sectional view of the ball member having abushing associated therewith, it being understood that the bushing isinserted in the ball member after the insertion of the ball member inthe corresponding socket;

FIG. 7 is a vertical, enlarged sectional view showing a typicallaminated metallic composite material adapted to be utilized in thehelix strip;

FIG. 8 is an enlarged, vertical sectional view showing a lcarginatedcomposite strip construction similar to FI FIG. 9 is a vertical,sectional view showing the initial insertion of the ball member inoperative relationship with the socket member;

FIG. 10 shows the further insertion of the ball member;

FIG. 11 shows continued insertion of the ball member;

FIG. 12 shows almost complete insertion of the ball member;

FIG. 13 illustrates a substantially cylindrical blank of metal which canbe utilized in fabricating a helix intended to constitute the helicalball member;

FIG. 14 illustrates the step of cutting the helix;

FIG. 15 illustrates the initial step of severing the helix from the coreof the cylindrical blank;

FIG. 16 illustrates the severance of the helix from the core; and

FIG. 17 illustrates the step of compressing the helix prior to thespherical generation thereof.

DESCRIPTION OF THE BEST EMBODIMENTS CONTEMPLATED Referring to thedrawings and particularly to FIGS. 1-2 thereof, of show a ball andsocket rod end bearing 10 which includes a socket member 12 and a ballmember 14 mounted in the socket member 12. The socket member 12 has anextension 16 which may be threaded or otherwise configured to receivethe corresponding extremity of a rod, link or other element intended tohave the rod end bearing 10 mounted thereupon. The socket member 12 hasa spherically configured race 18 provided therein for the reception ofthe correspondingly spherically configured external surface 20 of theball member 14.

The ball member 14 is formed from a compressed helical member 22, thecoils or turns 24 of the helix being compressed in operativerelationship with each other in a manner to be described in greaterdetail below. The helix 22 defines a bore 26 for the reception of acorresponding shaft or bolt shank or other cylindrically configuredmember adapted to be inserted therein.

The helix may be fabricated from strip material by conventional springwinding techniques, although it will be necessary to compress the coilsor turns 24 of the helix into engagement with one another and toestablish a precision I.D. prior to generating the external sphericalsurface upon the helix.

In any event, after the fabrication of the helix in the cylindricalconfiguration shown in FIG. 4 of the drawings, the spherical outersurface 20 is ground or out upon the helix while it is maintained in thecompressed condition shown in FIG. 4. Because of the fact that thespherical outer surface 20 is fabricated by grinding or cutting the sameupon the external surface of the helix, tolerances may be maintainedbetween the spherical race 18 ofthe socket member 12 and the sphericallygenerated outer surface 20 of the ball member 14 which cannot beachieved with other ball and socket constructions.

After the generation of the spherical surface 20 on the helix 22, theball member 14 is ready for insertion into the corresponding race 18 ofthe socket member 12. However, if the corresponding coils or turns 24 ofthe helix 22 were unwound into a flat strip similar to that from whichthey were wound, the development would be similar to that shown in thestrip 32 of FIG. 5 wherein the outer extremities of the strip 32represent the most severely cut or ground portions of the strip whilethe intermediate section of the strip represents the intermediatesection of the ball member 14.

Prior to the compacting or compressing of the coils or turns 24 of thehelix 22 into operative engagement with one another, the oppositeextremities of the helix are rough ground to eliminate the possibilitythat the extremities of the helix might cause the deformation ofadjacent coils or turns of the helix 22 when the helix 22 is placed in apress or die to bring the adjacent coils or turns 24 of the helix intooperative engagement with one another. Furthermore, since the grindingof the extremities of the helix 22 substantially reduces the crosssection thereof, said extremities are spot welded to the adjacent turnsor coils 24, as best shown at 34 in FIG. 2 of the drawings. It isdesirable that the last two or three turns or coils on each end of thehelix be spot or fusion welded to each other to provide stability of thefeather edged portion of the last turn.

The helical ball member 14 is shown in FIG. 6 as having a bushing 38mounted in the bore 26 thereof. The bushing is of cylindricalconfiguration and has a preformed flange 42 adapted to abut theleft-hand extremity of the helical ball member 14. The right-handextremity of the bushing is adapted to be swaged over a correspondingwasher 44 to maintain the bushing in operative relationship with thebore 26 of the helical ball member 14. In addition, to prevent relativerotation betweenv the bushing 38 and the adjacent wall of the bore 26,the bushing may be provided with one or more splines 46 which areengaged in corresponding slots or recesses formed in the wall of thebore 26. Therefore, relative rotation between the bushing 38 and thewall of the bore 26 is prevented which insures that the rotation of ashaft within the bore of the bushing 38 will not tend to cause thedistortion of the helical ball member 14. Furthermore, the bushing 38tends to maintain the adjacent turns or coils of the helix 22 inintimate engagement with one another to insure that the sphericallygenerated surface 20 will be integrally maintained in engagement withthe corresponding race 18, particularly in applications wherein it isdesired to have little or no bolt up load on the ball.

It is contemplated that any type of metallic material may be utilized infabricating the ball member 14. If the material is metal, it can bewound as a flat wound spring on conventional spring winders so long asit has twenty per cent or more elongation at room temperature. 1f thematerials are extremely hard and with less than twenty per centelongation, an alternative method of fabricating the initial continuoushelix 22 is utilized, said method to be described in greater detailhereinbelow. Of course, it is not intended that the teachings of theinvention be limited to the utilization of any particular metallicmaterial since it is conceivable that other materials, such as suitableplastics, might be utilized and that such techniques as injectionmolding be applied in the fabrication of the continuous helix 22.

Furthermore, it is also contemplated that the spring strip from whichthe helix 22 is fabricated may be coated with various types ofmaterials, such as trifluroethylene, to provide self-lubricatingcharacteristics or that the strip may be coated with other types ofsemipermanent lubricants, such as lubricants incorporating a highpercentage of molybdenum.

Moreover, bimetallic spring strips, such as the strip 52, shown in FIG.7 of the drawings, may be utilized to achieve desirable bearing actionresulting from the cooperative relationship of laminated metals 54 and56. In addition, end laminations such as the end lamination 62 areprovided on the strip 64 of FIG. 8.

The successive steps of insertion of the ball member 14 into operativeengagement with the race 18 of the socket member 12 are illustrated inFIGS. 9-12 of the drawings. Initial engagement of the right-handextremity of the ball member 14 brings one of the right-hand turns orcoils 24 of the helix 22 into operative engagement with thecorresponding edge 66 of the race 18 of the socket member 12. Continuedrotation of the ball member 14 will cause the successive engagement ofthe edge 66 of the race 18 with successive convolutions or turns 24 ofthe helix 22 to progressively draw the successive convolution or turns24 of the helix 22 into the race 18 of the socket member 12. v

The insertion of the ball member 14 into operative engagement with therace 18 of the socket member 12 can be accomplished by engagement of theleft-hand extremity of the ball member 14 by a mandrel which fits withinthe bore 26 of the ball member 14. This can be a hand tool or theinsertion of the ball member 14 can be accomplished by suitableautomatic devices. In any event, it should be noted that, for mostapplications, the convolutions of the helix 22 are left-hand wound foruse with right-hand threaded bolts and standard machine toolconfigurations during manufacture. The helix can be right-hand wound butit is preferred to use the lefthand configuration.

As previously indicated, the method of the invention includes stepsentailing the fabrication of the helix of the ball member 14 frommaterials of low elongation and considerable hardness, such as titaniumalloys, stellite, and the like.

In practicing the method of helix fabrication shown successively inFIGS. 13-17 of the drawings, a blank 70 of the desired material isprovided, said blank having a central cylindrical portion 72 from whichthe helix is to be cut and having reduced extremities 74 which definethe rough diameter of the bore of the helix to be formed and whichconstitute the extremities of the ultimate core member ejected from thehelix, in a manner to be described in greater detail below.

The blank is mounted in a machine tool indicated generally at 80 wherebyit may be rotated in the direction of the arrow 82 to be operated uponby a cutter 84 traveling in the direction of the arrow 86 to form thehelix 90. It should be noted that the showing in FIG. 14 is reversed andshows a right-hand wound helix, this showing being for the purpose ofillustration only since it is preferable that the helix be cut in alefthand configuration for the reason previously given hereinabove.

The length of the central cylindrical portion 72 of the blank 70determines the number of turns or convolutions to be formed in the helix90 plus the allowance required for compacting and for grinding theextremities of the helix 90 and for the possible coating or othertreatment of the successive convolutions of the helix In addition toutilizing conventional cutting tools such as the cutting tool 84, it isalso possible to utilize grinders or similar devices or to utilizesuitable abrasive discs in cutting the helix. After the cutting of thehelix 90 has been completed, the blank with the helix still securedthereto is placed in a die which includes a ram 94. The end of the ram94 is moved into engagement with the adjacent reduced extremity 74 ofthe blank 70 and the opposite-extremity 74 'is restrained againstmovement as the ram 94 moves against the corresponding extremity of thehelix 90 to strip the helix 90 from the resultant core 96.

After the helix 90 has been stripped from the core 96, the end turns arerough ground flat before compacting to avoid the coining of a depressionby the ends of the helix into the adjacent convolutions of the helix 90.The helix 90 is then placed in a compacting or compressing die 102 inwhich the successive convolutions or turns 104 thereof are driven intopositive engagement with one another. The pilot 106 of the die 102 isslightly undersized and the die ring 108 of the die 102 is slightlyoversized to allow a small amount of metal flow after the punch 112 hascompressed the helix 90. 90. The outer diameter equals that of the diering internal diameter and the internal diameter is reduced to the outerdiameter of the pilot 106.

Therefore, the ball member 14 can be fabricated from a wound helix 22 ora cut helix 90 depending on the elongation characteristics of the metalbeing utilized. However, once the helix has been fabricated thesuccessive steps of treatment of the helix are basically the same withthe exception that the compacting step illustrated in FIG. 17 isaccomplished at room temperature with materials of 7.5 percent or moreelongation and at temperatures greater than room temperature dependingon the materials with an elongation less than 7.5 percent.

After the compacting step has been accomplished, the bore 26 is formedin the helix. Subsequently, the two coils or more at the oppositeextremities of the helix are spot or fusion welded and the last coil ateach extremity is ground to provide a substantially vertical surface ateach extremity and a precise bearing width.

The resulting cylindrical helix is then placed on a spherical grinderand the rough, sphericity of the ball member 14 is achieved by machiningor grinding. The finished spherical ball member 14 is achieved bygrinding, burnishing or single pointing of the spherical outer surfacethereof.

If desired, the successive step of coating the resulting helical ballmember with a plastic coating such as trifluroethylene or with asuitable lubricant may take place.

The ball member can then be inserted in the race 18 of the correspondingsocket member 12 and the bushing 38 inserted in the bore of the ballmember 14.

I thus provide by my invention a ball and socket rod end bearingconstruction wherein the ball member is constituted by a continuoushelix which is threadedly engaged in the corresponding race of thesocket member and threadedly removable therefrom. I also provide methodsof fabricating the ball member from a continuous helix and offabricating the helix prior to the formation of the spherical surface ofthe ball member.

As previously indicated, the elimination of the swaging of the socketmember to retain the ball member in operative relationship therewithpermits the utilization of any desired material for the socket member.In addition, the precise formation of the ball member permits tolerancesto be achieved between the spherical surface of the ball member in thecorresponding race of the socket member which have not been attainablein prior art devices.

Moreover, because the assembly of the components of the ball and socketbearing does not entail the modification of the structure of either theball member or the socket member, a wide variety and range of materialscan be provided which could not be obtained in prior art devices.Moreover, the specific method of fabricating the ball member permits theutilization of materials and combinations of materials and lubricantsunattainable by prior art constructions.

I claim:

1. A spherical bearing comprising, in combination:

a one-piece annular socket member having a preformed, part-sphericalinternal race and a circular opening on each side of said racesubstantially smaller in diameter than the diameter of the race;

a ball member disposed in said socket member and having a part-sphericalouter surface in closefitting relation with said race, said outersurface having a diameter substantially larger than the diameters ofsaid openings so as to be confined rotatably in said socket;

said ball member comprising a continuous helix com posed of convolutionshaving shaped outer sides cooperating to form said part-spherical outersurface, and at least the convolutions larger than said openings beingfree to permit successive convolutions to be drawn into the socketmember through one of said openings during relative rotary movement ofsaid ball and socket members with the ball member in engagement with thesocket member in said one opening.

2. A bearing as defined in claim 1 in which said ball member has athrough bore defined by the inner sides of said convolutions.

3. A bearing as defined in claim 1 in which said ball member has flatend surfaces formed by the final convolutions adjacent the extremitiesof said helix, and said extremities are feather-edged to form said flatend surfaces, and further including means securing at least twoconvolutions of said helix together at each end to provide stability ofthe feather-edged portions.

4. A hearing as defined in claim 1 in which said helix is a flat woundspring having a machined outside surface.

5. A bearing as defined in claim 1 further including means for holdingsaid convolutions together after installation of said ball member insaid socket member.

6. A hearing as defined in claim 5 in which said ball member has a boretherethrough defined by the inner sides of said convolutions, and saidholding means include a bushing telescoped into said bore after assemblyof said ball member in said socket member.

7. A bearing as defined in claim 6 in which said bushing has endsabutting against said ball member at the opposite ends of said bore andholding said convolu tions against movement away from each other.

8. A bearing as defined in claim 6 in which said bushing isspline-coupled to said ball to prevent relative a mzztrgaaaaaa a arsatisfies... two convolutions of said helix are secured togetheradjacent each end of said bore.

10. A bearing as defined in claim 1 in which at least one of saidopenings is defined by a circular edge which acts as a thread fordrawing successive convolutions into said socket member.

11. The combination of:

a housing having a part-spherical socket of preselected diametertherein, and an opening into at least one side of said socket smallerthan said preselected diameter, said socket being defined by a single,integral part of said housing;

- and a ball disposed in said socket and having an outside surface witha diameter larger than said opening, said ball comprising a helixcomposed of convolutions having outer sides forming said outsidesurfaces and assembled in said housing with at least the convolutionslarger than said opening free to deflect and be drawn into the socketupon relative movement of the housing and the ball with the latterpressed against said opening.

12. The combination as defined in claim 11 in which said single,integral part of said housing defines an annular race with said openingon one side of said race and with the side of said race opposite saidopening closed to at least a diameter smaller than the diameter of saidball, whereby the latter is confined rotatably in said race by saidsingle integral part.

13. The combination as defined in claim 12 in which said opening isdefined by a circular edge of smaller diameter than the diameter of saidball, and engageable with the convolutions of said helix during relativerotation thereof to draw successive convolutions into said socket untilthe ball is rotatably confined in said socket.

14. The combination as defined in claim 12 further including means forholding said convolutions together, independent of said housing, afterinstallation of said ball in said socket.

15. The combination as defined in claim 14 in which said ball has athrough bore defined by the inner edges of said convolutions, and saidholding means include a bushing fitted tightly in said bore.

16. The combination as defined in claim 15 in which said bushing hasmeans on its opposite ends clamping said convolutions together.

17. In a bearing, the combination of: a one-piece housing defining aspherical socket of preselected diameter and having an opening on oneside smaller than said preselected diameter; and a spherical bearingthreadedly inserted into said socket through said opening and comprisinga helix having an outer spherical surface larger than any opening intosaid socket and corresponding to the sphericity of said socket.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent Nor3,680,930 a ed August 1 1972 Inventor(s) James R. Campbell I It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 1, line 41, delete "bearing" and substitute therefor beari'ngs.

Column 4, lines l-ll, delete the entire paragraph.

Column 5, line 25, delete "of" and substitute therefor Signed and sealedthis 1st day of May 1973.

D 51A .Lr) Attest:

EDT-JARED M. FLETCHER, JR. Attesting Officer ROBERT GOTTSCHALK'Commissioner of Patents

1. A spherical bearing comprising, in combination: a one-piece annularsocket member having a pre-formed, partspherical internal race and acircular opening on each side of said race substantially smaller indiameter than the diameter of the race; a ball member disposed in saidsocket member and having a partspherical outer surface in close-fittingrelation with said race, said outer surface having a diametersubstantially larger than the diameters of said openings so as to beconfined rotatably in said socket; said ball member comprising acontinuous helix composed of convolutions having shaped outer sidescooperating to form said part-spherical outer surface, and at least theconvolutions larger than said openings being free to permit successiveconvolutions to be drawn into the socket member through one of saidopenings during relative rotary movement of said ball and socket memberswith the ball member in engagement with the socket member in said oneopening.
 2. A bearing as defined in claim 1 in which said ball memberhas a through bore defined by the inner sides of said convolutions.
 3. Abearing as defined in claim 1 in which said ball member has flat endsurfaces formed by the final convolutions adjacent the extremities ofsaid helix, and said extremities are feather-edged to form said flat endsurfaces, and further including means securing at least two convolutionsof said helix together at each end to provide stability of thefeather-edged portions.
 4. A bearing as defined in claim 1 in which saidhelix is a flat wound spring having a machined outside surface.
 5. Abearing as defined in claim 1 further including means for holding saidconvolutions together after installation of said ball member in saidsocket member.
 6. A bearing as defined in claim 5 in which said ballmember has a bore therethrough defined by the inner sides of saidconvolutions, and said holding means include a bushing telescoped intosaid bore after assembly of said ball member in said socket member.
 7. Abearing as defined in claim 6 in which said bushing has ends abuttingagainst said ball member at the opposite ends of said bore and holdingsaid convolutions against movement away from each other.
 8. A bearing asdefined in claim 6 in which said bushing is spline-coupled to said ballto prevent relative rotation between the bushing and said convolutions.9. A bearing as defined in claim 8 in which at least two convolutions ofsaid helix are secured together adjacent each end of said bore.
 10. Abearing as defined in claim 1 in which at least one of said openings isdefined by a circular edge which acts as a thread for drawing successiveconvolutions into said socket member.
 11. The combination of: a housinghaving a part-spherical socket of preselected diameter therein, and anopening into at least one side of said socket smaller than saidpreselected diameter, said socket being defined by a single, integralpart of said housing; and a ball disposed in said socket and having anoutside surface with a diameter larger than said opening, said ballcomprising a helix composed of convolutions having outer sides formingsaid outside surfaces and assembled in said housing with at least theconvolutions larger than said opening free to deflect and be drawn intothe socket upon relative movement of the housing and the ball with thelatter pressed against said opening.
 12. The combination as defined inclaim 11 in which said single, integral part of said housing defines anannular race with said opening on one side of said race and with theside of said race opposite said opening closed to at least a diametersmaller than the diameter of said ball, whereby the latter is confinedrotatably in said race by said single integral part.
 13. The combinationas defined in claim 12 in which said opening is defined by a circularedge of smaller diameter than the diameter of said ball, and engageablewith the convolutions of said helix during relative rotation thereof todraw successive convolutions into said socket until the ball isrotatably confined in said socket.
 14. The combination as defined inclaim 12 further including means for holding said convolutions together,independent of said housing, after installation of said ball in saidsocket.
 15. The combination as defined in claim 14 in which said ballhas a through bore defined by the inner edges of said convolutions, andsaid holding means include a bushing fitted tightly in said bore. 16.The combination as defined in claim 15 in which said bushing has meanson its opposite ends clamping said convolutions together.
 17. In abearing, the combination of: a one-piece housing defining a sphericalsocket of preselected diameter and having an opening on one side smallerthan said preselected diameter; and a spherical bearing threadedlyinserted into said socket through said opening and comprising a helixhaving an outer spherical surface larger than any opening into saidsocket and corresponding to the sphericity of said socket.